Fossils from the formation of the solar system
In the early hours of a Saturday morning in October 2021, a spacecraft named Lucy rose from Cape Canaveral on a twelve-year journey to the edges of Jupiter's orbit, carrying with it the ambitions of a species that has long sought to understand its own origins. Named after a three-million-year-old human ancestor fossil, Lucy will travel nearly four billion miles to examine eight asteroids believed to be frozen witnesses to the solar system's birth. The mission is, in its deepest sense, a meditation on time — humanity using the bones of its past to reach toward the formation of its cosmic home.
- A $981 million spacecraft launched before dawn on a trajectory so complex that NASA's own science chief initially refused to believe it was possible.
- Seven of Lucy's eight asteroid targets are Trojan asteroids sharing Jupiter's orbit — ancient, untouched remnants that could rewrite our understanding of how planets formed.
- The mission demands extraordinary patience: gravity-assist flybys of Earth in 2022 and 2024 are needed just to build enough momentum to reach the outer solar system.
- Scientists genuinely do not know what they will find — no spacecraft has ever approached these asteroids, and their surfaces remain entirely unknown.
- Lucy carries lab-grown diamonds, Beatles lyrics, and the name of a paleoanthropologist's greatest discovery, threading human history into a mission about cosmic prehistory.
- With asteroid encounters beginning in the late 2020s and the final targets not reached until 2033, Lucy is a long bet on the value of deep, unhurried scientific inquiry.
Before sunrise on a Saturday at Cape Canaveral, an Atlas V rocket carried the spacecraft Lucy into the Florida sky, beginning one of NASA's most ambitious planetary science missions. Over twelve years and nearly four billion miles, Lucy will visit eight asteroids — seven of them Trojan asteroids orbiting Jupiter — believed to be pristine remnants from the solar system's earliest formation.
The spacecraft's name carries deliberate resonance. It honors a three-million-year-old human ancestor fossil discovered in Ethiopia, itself named after the Beatles song "Lucy in the Sky with Diamonds." NASA inscribed band members' lyrics and words from other luminaries onto a plaque aboard the craft, and the mission carries a disc of lab-grown diamonds as part of its scientific instruments. Donald Johanson, the paleoanthropologist who discovered the original fossil, attended the launch and described it as a convergence of humanity's past, present, and future.
Lucy's path is anything but straightforward. It will use Earth's gravity as a slingshot in 2022 and again in 2024 before passing an asteroid named Donaldjohanson in 2025 — a dress rehearsal for its instruments. The mission's principal scientist, Hal Levison, noted that despite sharing Jupiter's orbit, the Trojans are so widely scattered that collision risk is negligible.
The asteroid encounters will unfold across the late 2020s and early 2030s, with Lucy passing within six hundred miles of each target. After visiting five asteroids in Jupiter's leading Trojan cluster, the spacecraft will return to Earth in 2030 for a final gravity assist before reaching the trailing cluster and its last two targets in 2033. Scientists openly acknowledge they do not know what these ancient rocks will look like up close — making Lucy, in every sense, a journey into the unknown.
Before sunrise on a Saturday morning at Cape Canaveral, an Atlas V rocket lifted off carrying a spacecraft named Lucy into the Florida sky. The mission ahead was audacious in its scope: twelve years of travel across nearly four billion miles to visit eight asteroids, seven of them part of the vast swarms that orbit Jupiter in tandem with the gas giant itself. These Trojan asteroids, as they're called, are thought to be pristine remnants from the solar system's earliest days—witnesses to how planets formed and settled into their current orbits.
The spacecraft's name carries a particular weight. Lucy is named after skeletal remains discovered in Ethiopia nearly fifty years ago, a three-million-year-old human ancestor that revolutionized our understanding of human evolution. That fossil itself was named after a Beatles song, "Lucy in the Sky with Diamonds," a connection that NASA honored by inscribing band members' lyrics and words from other luminaries onto a plaque aboard the spacecraft. The mission also carries something more literal: a disc made of lab-grown diamonds, part of one of its scientific instruments. The symbolism was not lost on Donald Johanson, the paleoanthropologist who discovered the original Lucy fossil. He traveled to Cape Canaveral for the launch, describing the moment as a convergence of humanity's past, present, and future—a three-million-year-old ancestor spurring a mission that would reveal secrets about the solar system's formation.
The journey Lucy will take is anything but direct. The spacecraft will use Earth's gravity as a slingshot, making flybys in October 2022 and again in 2024 to gain enough momentum to reach Jupiter's orbit. Along the way, it will pass an asteroid named Donaldjohanson—a fitting tribute—between Mars and Jupiter in 2025, a kind of dress rehearsal for the instruments that will do the real science work. The mission's principal scientist, Hal Levison of Southwest Research Institute, noted that despite the Trojans' shared orbit with Jupiter, they are scattered so far from one another and from the planet that Lucy faces essentially no risk of collision as it approaches its targets.
The actual asteroid encounters will unfold across the late 2020s and early 2030s. Lucy will pass within six hundred miles of each target, close enough to gather detailed images and data. The largest asteroid it will visit spans roughly seventy miles across. The spacecraft draws power from two enormous circular solar wings, a design that had to function reliably across a journey of staggering distance. When Thomas Zurbuchen, NASA's science mission chief, first heard the proposed trajectory, he found himself skeptical. "You've got to be kidding. This is possible?" he recalled asking. The answer was yes, though the path required five separate asteroid encounters in the leading Trojan cluster, then a return to Earth in 2030 for another gravity assist that would redirect Lucy toward the trailing cluster, where it would visit two final targets in 2033.
Hal Weaver, a scientist at Johns Hopkins University overseeing Lucy's black-and-white camera system, expressed the genuine uncertainty that drives such missions. No one knows what these ancient rocks will reveal—whether they have mountains or valleys, pits or mesas. These asteroids are, in a real sense, fossils from the solar system's formation, and Lucy will be the first spacecraft to examine them up close. The mission cost $981 million, a substantial investment in understanding the solar system's deep history. As Lucy begins its long journey, NASA is preparing another mission for the following month, this one designed to test whether humans might someday alter an asteroid's trajectory—a different kind of exploration, one focused not on understanding the past but on protecting the future.
Citas Notables
That a human ancestor who lived so long ago stimulated a mission which promises to add valuable information about the formation of our solar system is incredibly exciting.— Donald Johanson, paleoanthropologist who discovered the original Lucy fossil
Are there mountains? Valleys? Pits? Mesas? Who knows? I'm sure we're going to be surprised.— Hal Weaver, Johns Hopkins University, Lucy's camera system lead
La Conversación del Hearth Otra perspectiva de la historia
Why name a spacecraft after a human ancestor? It seems like an odd choice for a mission to asteroids.
It's actually elegant. Lucy the fossil was named after a Beatles song, and that connection—between human discovery and artistic expression—appealed to NASA. They wanted the spacecraft to carry that same sense of wonder about origins, whether we're talking about human origins or the solar system's.
The mission takes twelve years and nearly four billion miles. Why such a long, complicated path?
Gravity is the answer. Lucy can't just fly straight to Jupiter. It needs Earth's gravity to slingshot it outward twice, gaining speed each time. It's like borrowing momentum from home to reach somewhere impossibly far away.
These Trojan asteroids—why are scientists so interested in them specifically?
They're thought to be unchanged since the solar system formed. Everything else has been battered and altered over billions of years, but these asteroids in Jupiter's orbit have mostly been left alone. They're like time capsules.
What happens if Lucy hits one of these asteroids?
Essentially nothing. They're so scattered across space that the odds are nearly zero. The biggest risk isn't collision—it's the sheer distance and the need for everything to work perfectly for twelve years.
The spacecraft carries lab-grown diamonds. That seems symbolic.
It is. Diamonds are durable, they last. It's a way of saying this mission, this knowledge we're gathering, matters across time.